<html> Dave, It depends an awful lot on the individual piano - that's why it is a little hard to answer your question.  If the tone is clear and you can hear double octave beats clearly, you can simply try to tune on the sharp side of pure 4:1 double octaves.  In other pianos you can work with the octave + 5th (17th) and tune them for consistency.  Just how the 17ths are tuned really depends on the scale, though. In noisier pianos where all the beats may not be as clear, you can usually still use the speed of the 2:1 beat as your guide to consistency - pull the string quite sharp, and slow it down to where you can hear the beat clearly and consistently, and gradually speed the beats up as you work into the top octave to the point where they are almost too fast to hear. Or, set Cybertuner to OTS 9 and tune away . . . Don Mannino RPT At 07:54 AM 4/11/2003 -0700, you wrote: <blockquote type=cite class=cite cite>A client has asked me to put more stretch in the high treble. Simply put, how do I do this as an aural tuner?  I know it can be subjective, but I also need a way to make it even. Dave Streit, RPT AAA Piano Service Portland, OR</blockquote></html>